1. Field of the Invention
The present invention relates to apparatus for protecting a partially or fully submerged metallic structural element against corrosion from air, water or a combination of both.
2. Description of the Prior Art
It is common to protect the submerged portion of a metallic structural element from corrosion by cathodic methods. Such cathodic protection is expensive and only protects the submerged portion of the metallic element and not the portion thereof in the splash zone. Corrosion protection has also been provided for both the submerged and air-exposed portions of such metallic elements by means of noncorrosive coatings. When such coatings fail, however, they cannot readily be replaced on the submerged portion of the metallic element, and it is expensive to replace such coatings on the splash zone portion of such element. It has also been proposed to add concrete sleeves around such metallic elements. This process is quite expensive, and additionally, such concrete sleeves are difficult to install. For sections of metallic elements above water and exposed to air and mixture, the usual practice has been to apply noncorrosive coatings, such as paints, metallic coatings, epoxies and the like to protect against corrosion. These methods have been expensive and the service life is limited.